Only show DownloadItemsSheet if there's more than one download item
Summary:
This was caused by using the downloadCount (which is the total number of times the item has been downloaded), rather than the length of the list of download items.
BUG:413437
Test Plan:
With patch: Shows "Install..." for all items (with other than one user download)
Without patch: Shows "Install..." only for items with more than one download item
Reviewers: KNewStuff, Frameworks, ngraham
Reviewed By: ngraham
Subscribers: kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D25165